Half
Waveplates |
| |
| Half wave plates are convenient means
for reorienting the polarization in order to meet the requirements
for a particular optical configuration, without rotating the laser.
Half wave plates convert left circularly or elliptically polarized
beams into right circularly or elliptically polarized light, and
vice versa. |
| The thickness of a half waveplate
is such that the phase difference is 1/2-wavelength (true-zero order)
or some multiple of 1/2-wavelength (multiple order). |
| A linearly polarized beam
incident on a half waveplate emerges as a linearly polarized beam
but rotated such that its angle to the optical axis is twice that
of the incident beam. Therefore, half-waveplates can be used as
continuously adjustable polarization rotators. Half-waveplates are
used in rotating the plane of polarization, electro-optic modulation
and as a variable ratio beamsplitter when used in conjunction with
a polarization cube. |
|
Half Waveplates